For many high precision electronic circuits, the various components, particularly semiconductor devices such as transistors, must meet stringent design standards. Often, even if design and manufacturing tolerances are within the required range, the actual performance of a particular transistor is not the same as specified. In many cases, the discrepancy is not discovered until after the device is soldered onto the circuit board. This makes the task of identifying and subsequently replacing the faulty device time consuming and difficult. In addition, reworking the circuit board can often introduce other defects. To avoid this situation, it is desirable to test the performance of the transistors before they are soldered to the circuit board.
Various techniques have been utilized to attach or clamp a transistor to a circuit board for testing prior to soldering. However, these techniques suffer from one or more drawbacks. First, conventional transistor testing clamps tend to apply pressure to the transistor leads in a manner which is not uniform or well controlled. As a result, repeated testing of the same transistor may produce different results since the electrical characteristics of the contact made between the transistor lead and the testing equipment depends on the contact force applied to the leads. In addition, the non-uniform pressure can damage the transistor leads sufficiently to affect the performance of the transistor. A further drawback which is present in various conventional transistor clamping fixtures is the interaction between the clamp and the electrical fields of the transistor. During high precision testing, this interaction can skew the test results, resulting in misleading performance evaluations.
Accordingly, it would be advantageous to provide a transistor clamping fixture which allows a transistor to be temporarily attached to a circuit board without the use of solder. It would be also advantageous if such a clamping fixture applied pressure to the transistor leads in a uniform and repeatable matter. It would be a further advantage if such a transistor clamping fixture produced only minimal interference with the electric fields surrounding the operating clamped transistor.